• Title/Summary/Keyword: Spin glass

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Optical and Conduction Properties with the Thickness Variation of the Light-emitting Layer in PVK-Based PLED (PVK계 PLED에서 발광층의 두께 변화에 따른 광학 및 전도 특성)

  • Jang, Kyung-Uk;Ahn, Hee-Cheul;Shin, Eun-Cheul;Lee, Eun-Hye;Yoon, Hee-Myung;Chung, Dong-Hoe;Ahn, Joon-Ho;Lee, Won-Jae;Kim, Tae-Wan
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.11a
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    • pp.373-374
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    • 2007
  • We have fabricated polymer light-emitting diodes(PLED) in a structure of Glass/ITO/PVK/Al. Poly(N-vinylcabazole) (PVK) was deposited on the ITO glass with the spin coating method. PVK thickness is respectively 500nm, 300nm, 250nm and 200nm with the spin coter rotation speed of 2000, 3000, 4000 and 5000rpm. V-I, wavelength-transmittance, P-L and SEM of the fabricated devices were measured. From the result of P-L measurement, it was kept the optic properties of PVK raw powder when PVK thickness is 250nm. The knee-voltage of PVK PLED with 250nm thickness was 7V.

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SPIN GLASS BEHAVIOR AND ANTIFERROMAGNETIC EXCHANGE COUPLING IN LASER-DEPOSITED $Zn_{1-x}Co_xO$ THIN FILMS

  • Kim, Hyojin;Kim, Dojin;Ihm, Young-Eon;Kim, Jae-Hyun;Choo, Woong-Kil
    • Proceedings of the Korean Magnestics Society Conference
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    • 2002.12a
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    • pp.94-95
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    • 2002
  • Recently, we have seen a rapid advance in the evolving field of spin electronics (or spintronics). In spintronics, some feasibilities of new electronic applications utilizing spin degree of freedom have been explored. Diluted magnetic semiconductors (DMSs) are premising materials for spintronics because they have both charge and spin degree of freedom in a single substance. DMSs are refereed to semiconductor alloys in which some atoms are randomly substituted for by magnetic atoms. (omitted)

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Optimization of Spin-On-Glass Planarization Process Using Statistical Design of Experiments (통계적 실험계획법을 이용한 SOG 평탄화 공정의 최적화)

  • 임채영;박세근
    • Journal of the Korean Vacuum Society
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    • v.1 no.1
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    • pp.198-205
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    • 1992
  • Abstract-Planarieation technology, which is essential to VLSI, has been developed using non-etch back Spin- On-Glass (SOG). Process factors for 1.5 micron double metal technology are optimized by the statistical design of experiments. Optimum conditions are found to be a process with twice SOG coating, sufficiently long hot plate baking at 300t, and furnace curing for 40 minutes below 400$^{\circ}$C.

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Preparation and Analysis of the SOG Films (스핀-온-글라스 박막의 제조와 분석)

  • 임경란;최두진;박선진
    • Journal of the Korean Ceramic Society
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    • v.29 no.11
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    • pp.863-869
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    • 1992
  • A SOG(spin glass) solution with excellent wetting to Si wafers was prepared by acid-hydrolysis of Si(OEt)4 and Me2Si(OEt)2. The solution was spin coated on Si wafers, and effects of heat treatment of the film were characterized by TG/DTA, FTIR and Ellipsometry. Silica film was obtained by heat treatment at $600^{\circ}C$ within one hour, but heat treatment at 80$0^{\circ}C$ caused interfacial oxidation of the silicon substrate. Unexpectedly silica films with much better adhesion were obtained by curing at $600^{\circ}C$ for over 30 min. than those obtained by thermal oxidation.

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Random Access Memory utilizing Spin Tunneling Giant Magnetoresistance Effect (스핀 터널링 거대자기저항 효과를 이용한 랜덤 엑세스 메모리)

  • 박승영;최연봉;조순철
    • Proceedings of the IEEK Conference
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    • 1999.06a
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    • pp.950-953
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    • 1999
  • Spin tunneling giant magnetoresistance effect was studied to utilize in the application of random access memory. Ferromagnetic/Insulator/Ferromagnetic films were sputtered on glass substrates and perpendicular current was applied. Measurements of magneto- resistance of the junction showed 8.6% of MR ratio. Voltage output depends on the magnetization directions of the write line and read line, thus enabling the system to be used as a random access memory

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COLLINEARITY AND SPIN FREEZING

  • Vincze, I.;Kemeny, T.
    • Journal of the Korean Magnetics Society
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    • v.5 no.5
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    • pp.343-350
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    • 1995
  • An overview will be given on recent Mossbauer and magnetization investigation of the applied field dependence of the magnetic properties of typical systems without strong magnetic anisotropy and showing the absence of magnetic saturation in high fields (including iron-rich spin glass (amorphous $Fe_{93}Zr_{7}$, soft ferromagnets (amorphous $Fe_{88}Zr_{12}$, $Fe_{70}Ni_{20}Zr_{10}$ and $Fe_{88}B_{12}$) and pure Fe). The results emphasize that shape anisotropy due to surface irregularities causes misalignment between the magnetization and the applied field in the otherwise collinear magnetic structure.

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Fabrication and Properties of ferroelectric BST thin films prepared by sol-gel method (II) - effect of ultrasound on properties of thin film (졸-겔법에 의한 강유전 BST 박막의 제조 및 특성(II) - 초음파의 효과)

  • 이진홍;박병옥;이승엽
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.11 no.6
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    • pp.252-258
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    • 2001
  • ($Ba_{0.7}Sr_{0.3})TiO_3$thin films were perpared on ITO-coated glass substrate by spin-coating method. The sol was sonicated in an ultrasonic bath to promote homogenization and the results were compared with untreated case. By application of the sonication process, crystallization temperatures of films were reduced, microstructers of films were more uniform and denser and the surface roughness of the films was lower from 8.4nm to 5.6nm. In addition, optical transmittances and electrical properties of films prepraed from sonicated sol were superior to those of films from untreated.

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Magnetoresistance of Co/Cu/Co Spin Valve Sandwiches

  • Park, S. J.;Park, K. L.;Kim, M. Y.;j. R. Rhee;D. G. Hwang;Lee, S. S.;Lee, k. A.;Park, C. M.
    • Journal of Magnetics
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    • v.2 no.1
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    • pp.7-11
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    • 1997
  • The dependence of magnetoresistance (MR) ratio on various variables like the thickness of the second Co layer, on the presence of cap layer, on deposition field (Hdep) and on annealing in Co/Cu/Co sandwiches was investigated. Spin-valve sandwiches were deposited on the corning glass by means of the 3-gun dcmagnetron sputtering at a 5 mTorr partial Ar pressure and room temperature. The deposition field was varied from 70 Oe to 720 Oe. The MR curve was measured by the four-terminal method with applied magnetic field up to 1000 Oe perpendicular to the direction of a current in the film plne. The MR ratio of glass/Fe(50${\AA}$)/Co(17${\AA}$)/Cu(24${\AA}$)/Cot(${\AA}$) fabricated by making 50 ${\AA}$ of Fe buffer layer has the maximum value of 8.2% when the thickness of the second Co layer was 17${\AA}$and the deposition field was 350 Oe. In the case of glass/Fe(50${\AA}$)/Co(17${\AA}$)/Cu(24${\AA}$)/Cot(${\AA}$) with Cu cap layer on top, the decrease in the MR ratio seemed to relate with the oxidation of the second Co layer. Samples prepared with deposition field showed greater MR ratios through the formation of more complete spin valve films. After annealing for 2 hours at 300$^{\circ}C$, the MR ratio of the samples prepared with deposition field decreased rapidly while the MR raito of the sample prepared without the field remained.

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Properties of Organic Light Emitting Diode with ITO/MEH-PPV/Al Structure on Heating Temperatures (열처리 온도에 따른 ITO/MEH-PPV/Al 구조의 유기 발광다이오드의 특성연구)

  • 조중연;장호정
    • Journal of the Microelectronics and Packaging Society
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    • v.10 no.4
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    • pp.35-38
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    • 2003
  • Polymer light emitting diode (PLED) with an ITO/MEH-PPV/Al structure were prepared by spin coating method on the ITO (indium tin oxide)/glass substrates, using poly(2-methoxy-5-(2-ethylhexoxy)-1,4-phenylenevinylene (MEH-PPV) as the light emitting material. The dependence of heat treatment on the electrical and optical properties for the prepared PLED samples were investigated. The luminance decreased greatly from 630 cd/$\m^2$ to 280 cd/$\m^2$ at 10V input voltage as the heating temperature increased from $65^{\circ}C$ to $170^{\circ}C$. In addition, the luminance efficiency was found to be about 2 lm/W for the sample heat treated at $65^{\circ}C$. These results may be related to the interface roughness and/or the formation of an insulation layer, which is caused by the reaction between electrode and MEH-PPV organic luminescent film layer.

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